Many antibodies specific for viral core proteins or non-structural proteins have the capacity to block viral infection if they are introduced into the cytosol of virus infected cells. Recent advance in understanding antibody folding indicate that antibodies have the ability to properly fold and bind antigen when expressed in the cytosol. Therefore, cells, or transgenic animals expressing a cytosolic form of an antibody capable of interfering with viral replication should be resistant to viral infection. Using electroporation to induce antibodies into cells we have identified monoclonal antibodies that block infection with influenza viruses, and have begun to clone the corresponding genes from hybridoma cells with the goal of creating animals resistant to influenza virus infection.